Portable power supply



FIG. 1 is a front elevation view of a portable power supply showing thenew design;

FIG. 2 is a back elevation view thereof;

FIG. 3 is a left-side view thereof;

FIG. 4 is a right-side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a top-left perspective view thereof;

FIG. 8 is a working status of the perspective view thereof; and,

FIG. 9 is a detached status of perspective view thereof.

CLAIM The ornamental design for a portable power supply, as shown anddescribed.